Emerging vehicular networks in the forms of Intra-Vehicle (InV), Vehicle-to-Vehicle (V2V), and Vehicleto- Infrastructure (V2I) communications will enable a variety of applications for safety, traffic efficiency, driver assistance, as well as infotainment to be incorporated into modern automobile designs. At the same time, networked Electronic Control Units (ECUs) are increasingly being deployed in automobiles to realize functions such as engine management, air-bag deployment, and even in intelligent brake systems. In addition, users now expect to sit in an automobile and have their brought-in devices, and beamed-in services harmoniously integrated with the built-in interfaces inside the automobile. Thus, widespread adoption of vehicular networks is fast becoming a reality and critical data is being exchanged with-inside and with-outside vehicle via vehicular networks. This chapter gives an overview of this emerging area of vehicular networks, its potential applications, its potential wireless technologies for data exchange, and its research activities in the Europe, the United States (U.S.), Japan, and Singapore.